At work, I use two computers: one Windows machine for intranet and mail, one Ubuntu machine on a separate network for development. In order to easily switch between the two I use a simple USB KVM switch (a Newstar) so I can use a single mouse and keyboard for both machines.

Using the hardware key on the switch itself, I can switch between the two computers. However, I don't want to stretch my arm. That's physical effort, and it's not what IT is for.

On the Windows machine, I can double-tap Scroll Lock to trigger the switch to the Ubuntu machine. On the Ubuntu machine, Scroll Lock does nothing - xev says it sends a KeyPress/KeyRelease event with keycode 78, but the scroll light stays off and more importantly, the switch does nothing.

I have found a solution telling me to add 'add mod3 = Scroll_lock' to xmodmap, but while that makes the light blink it doesn't trigger the switch.

Since I can double-tap Scroll Lock in text mode and make it trigger the switch, I'm guessing either X doesn't fully forward the keypress or something else swallows the event.


How can I make this work? Or more accurately, how can figure out what sort of input will trigger the switch so I can emulate it in Ubuntu?

  • Any luck on this? – wlraider70 Aug 26 '18 at 3:43
sudo xmodmap -e "add mod3 = Scroll_Lock"

You forgot to add -e.

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